1. Field of the Invention
The present invention relates to a mechanical rotational drive with a bar-like torsion element.
2. Discussion of Background Information
A variety of mechanical rotational drives are known. In particular, such drives are used in space engineering in order, e.g., to effect one-time actuations of external structures on satellites, e.g., the extension of antennas or solar panels. Such rotational drives have the advantage that they can be preloaded with a mechanical energy on earth before the start of a space mission, which energy is then emitted in space to perform the desired actuation. This actuation is therefore not dependent on the very limited electric energy available in space.
However, with satellites or other spacecraft such drive solutions call for a high degree of reliability and a great position accuracy of the extended antenna or the extended solar panel after extension. In order to achieve this aim, conventional mechanical systems are complex in design, heavy and therefore expensive. A serious problem with conventional mechanical systems is the bearing clearance that as a rule does not guarantee an exact positioning of an external structure to be extended. To this end separate mechanical means, such as, e.g., engagement devices, are frequently necessary, the provision of which, however, in turn increases the weight and thus the expense and also the complexity of the overall arrangement, which regularly has a negative impact on the reliability of the overall system.
DE 37 40 756 A1 relates to a torsionally elastic hollow shaft for transmitting torque which, for damping torsional vibrations, is combined with an outer or inner torsion-resistant tubular body in a coaxial arrangement, with the occurrence of friction. The hollow shaft is thereby made of a fiber composite and is connected directly to connection parts for introducing the torque and takes on only the transmission of torque, whereas the torsion-resistant tubular body produces friction forces relative to the twisted shaft. The friction can be produced by surface contact or by internal friction in liquid or solid damping media.
DE 696 08 930 T2 relates to communication satellites, space stations, and the like which utilize solar panel arrays as a main source of power. The document describes a hybrid solar panel array that employs a combination of rigid solar panels with semi-rigid solar panels or with flexible solar panels.
DE 696 04 165 T2 relates to a device for positioning a solar panel on a spacecraft. The device comprises a heat-sensitive drive mechanism suitable for causing the panel to be displaced relative to the body of the spacecraft automatically as a function of the direction of incidence of the solar radiation on the spacecraft.
DE 689 02 110 T2 relates to an antifriction self-motorized joint and an articulated unit, e.g., a satellite solar panel, provided with such joints. The joint includes two braces suitable for rolling onto each other through two cylindrical surfaces.